The Internet and the World Wide Web (“Web”) have changed the landscape of information delivery and affected numerous aspects of life. One benefit of this technological development is the ability to conduct business transactions globally via the Internet. As the volume of commerce conducted over the network continues to increase, collections of business units or organizations are working together to pool resources and expertise in order to achieve a common business objective. Organizations are sharing services and resources across enterprise boundaries in order to undertake collaborative projects and offer services that could not be provided by individual organizations.
A growing array of technologies has emerged to help bridge the gaps between people, time and geography in such collaborative environments. This includes the development of Web Services Choreography Description Language (WS-CDL) which is an XML-based language that describes peer-to-peer collaboration of participants by defining, from a global viewpoint, their common and complementary observable behavior, where messages are exchanged to accomplish a common operational goal. In particular, WS-CDL is targeted at composing interoperable, collaboration between any type of participants regardless of the supporting platform, programming model and security domain of the hosting environment.
Stated differently, WS-CDL describes the externally observable behavior of a business entity in an inter-organizational workflow process. WS-CDL provides a means to define the rules or protocols of collaboration between multiple participants from different security domains without revealing the internal operation. In general, WS-CDL specifies the participants, the type of information being exchange during the interaction of the participants and the options available to continue the interaction.
In addition, WS-CDL is frequently used in conjunction with the Web Services Business Process Execution Language (WS-BPEL). WS-BPEL is a programming language designed to allow collaborative execution of activities and service orchestration e programming by different groups of people. The emphasis of WS-BPEL is partitioning workflow processes into WS-BPEL process stubs with specific interaction between the WS-BPEL process stubs. One approach of deriving WS-BPEL for a workflow process is for multiple participants to agree on a specific choreography defined in WS-CDL in order to achieve a common goal. The WS-CDL is then used to generate WS-BPEL process for each participant. Stated differently, the WS-CDL choreography is similar to a global contract to which all the participants are committed while the WS-BPEL are the steps required to execute the global contract.
However, WS-CDL suffers from insufficient separation of meta-model and syntax, has limited support for certain use case categories and the format grounding is not comprehensible. Beyond that, it is unclear whether all WS-CDL concepts can be mapped to WS-BPEL without active human intervention. Improvements in the automatic generation of executable processes (WS-BPEL) from inter-organizational workflows (WS-CDL) are certainly needed.